At how may weeks old can I start telling one breed of chick from another? It has been a few years since I had baby chicks and just got in 25 plus 1 rare exotic. Half are mine and half a friends, 5 of mine are Araucana and I have come to the conclussion that no two of these are alike. Anyone that got chicks from McMurray hatchery know what kind of "rare exotic chick" they are sending out? Thanks!!